In the operation of a plurality of variable displacement pumps, it is desirable to have the pump controls of each pump interconnected. Further, it is desirable to provide each pump control with means for responding to load, compensating for pressure, and controlling a servo valve of the pump controls in response to a common pressure signal that is of a magnitude that is controlled relative to the magnitudes of the pump discharge pressures.
While providing these control functions, it is desirable to maintain the pump control elements in a compact housing and maintain the number of conduits and connections at a minimum.
These pump control assemblies are often used on work vehicles, such as an excavator for example, which is subject to rough treatment and abuse. By so providing the critical elements in a compact package, the elements are protected from damage, thereby avoiding waste of material and time.
This invention therefore resides in interconnected pump control assembies of at least two variable displacement pumps having control means responsive to a signal relating to the discharge pressures of the pumps and having interconnecting fluid pathways between first and second biasing means of each pump control being positioned in a pump control housing.